1. Field of the Invention
The present invention relates to a cervical orthosis, and more particularly to a structure of a cervical orthosis which is small, lightweight and easily fit on the neck and causes a comfortable feeling in use. The present invention does further relate to a method of mounting a fastener on objects.
2. Prior Art
Cervical vertebrae is the skeleton which supports the head having substantial weight, suspends the upper limbs and has a large movable range. Hence, it can be said that cervical vertebrae is the spine likely to undergo disorders (injuries, derangement, impairment, etc.) and to age. In fact, cervical vertebrae is known as a part apt to easily have disorders even from a minor car accident, and many people suffer from whiplash injury and its sequela or aftereffect.
Cervical vertebrae undergo also other disorders than the traumatopathy typically from the car accidents. In detail, it is known that spontaneous subluxation of atlanto-axial joint (generally anterior spontaneous subluxation) is seen in about 30% of cases of rheumatoid arthritis and causes not only local pain but also severe neurological disorders occasionally. The so-called conservative therapy using various cervical orthoses is usually applied to those disorders of cervical vertebrae. The cervical orthoses are classified on the basis of design generally into "Cervical (or orthopedic) collars", "Philadelphia collars", "Moulded cervical orthoses" and "Cervical orthoses with uprights", and a suitable type of orthosis is adopted in consideration of doctors' prescription on specific disorders as well as advantages and disadvantages of those cervical orthoses.
The cervical collars are low in control effect on such movements of cervical vertebrae as bending and extending forward and backward, rotating and lateral flexion but can be easily handled including adjustment of height and hardness. The cervical collars are more superior in keeping local temperatures and causing users to have a feeling of being firmly supported or of comfortableness in comparison with others at present. In addition, ready-made articles of the collars are available usually in four types LL, L, M and S and cheaply.
The Philadelphia collars are made of expanded polyethylene plate formed and characterized in a feeling of excellent comfortableness in use. The Philadelphia collars are enhanced in supporting effect for submaxilla and occiput of the head in comparison with the cervical collars, so that the collars restrain normal bending and extending movements of cervical vertebrae by about 30% but are said to be poor in restraining effect on movements as rotation and latexion.
The moulded cervical orthoses and the cervical orthoses with uprights are both extremely high in supporting effect for the head and in controlling effect on the movements of cervical vertebrae and are necessary to severe disorders, such as loss of supportability of skeleton due to deficiency or destruction of cervical vertebrae. (Usable for unstable vertebrae which require higher fixing effect than these orthoses is only the "skull traction".) The moulded cervical orthoses and the cervical orthoses with uprights are made of hard materials by moulding according to specifications of users to thereby he expensive and poor in comfortableness in use.
Various types or configurations of cervical orthoses have been hitherto proposed as above. An inherent clinical and therapeutic purpose of cervical orthoses is to mitigate pain and myopalmus caused by increment of movability of cervical vertebrae. However, excessive therapy or long use of the orthoses does or may cause muscle force lowering, myoatrophy, arthrogryposis, conditions turning worse occasionally, or psychogenic disorders originated from orthoses-dependency. Hence, orthoses which are mild in operation should be used at a minimum from necessity in a short term. Moreover, cases needing cervical orthoses superior in the control effect are rare practically. Most of the patients (whose disorders can be cured ambulantly and who wear orthoses in their daily life) may be caused to be conscious of their disorders by means of a prescribed light or mildly functional orthosis and lessen by themselves movement of their necks, thereby generally achieving the purpose of cure. Furthermore, easy attachment and removal of orthoses is an important requirement for selecting a a suitable orthosis in view of possible dactyl deformity or hypokinesis (diminished or slow movement) as seen in most of patients having cervical vertebrae disorders caused, for example, by chronic rheumatism. In this respect, the moulded cervical orthoses or the cervical orthoses with uprights should not be adopted.
Cervical orthoses to be prescribed or suitable for the patients (whose cervical vertebrae disorders are light or relatively mild) are those providing feelings of comfortableness and support in use but restraining excessive movement of cervical vertebrae without improved capacities of sustaining the weight of the head and stopping the extending and bending movement of cervical vertebrae.
Resulting from placing importance on these points and pursuing only the comfortableness in use and temperature-keeping efficiency, most of the conventional cervical orthoses were quite poor in the control effect.
Getting sticky with perspiration at the affected part upon use of cervical orthoses have been hitherto not considered. Some conventional cervical orthoses using sponge or urethane foam for providing "comfortableness" have caused aged persons, patients wishing to avoid skin irritation or those using the orthoses at night to feel uncomfortable. Under the circumstances, a cervical orthosis which has the control effect to some extent; does always provide excellent comfortableness in use; and is cheap to manufacture has been expected.